Carburetor



June 20, 1939.

W. SCHWIER CARBURETOR Filed Aug. 10, 1937 5 Sheets-Sheet 2 June 1939- w. SCHWIER 2,163,499

CARBURETOR Filed Aug. 10, 1937 5 Sheets-Sheet 4' Q y m i Schwien w. SCHWIER June '20; 1939.

CARBURETOR Filed Aug. 10; 1937 5 Sheets-Sheet 5 mfii it I Patented June 20, 1939 UNITED STATES eater orrlcs I Application August 10,

2 Claims.

This invention aims to provide a carburetor of the down draft type, comprising novel means for delivering the fuel to the point of discharge within the carburetor, the necessity for a fuel pump being done away with, there being a single idling passage in the carburetor, and a single running passage therein, each controlled by valves, the valve for the idling passage being under the governance of an operator, and the valve for the running passage being controlled by the movement of the Venturi member, the Venturi member being operatively connected with the throttle valve.

The invention aims to provide a carburetor wherein floats, diaphragms, and other more or less inert impediments to a proper flow of the fuel may be dispensed with. A further object of the invention is to provide a device of the class described wherein there is a proper and progressive synchronization of the air and fuel supplying means, the operator always having the action of the carburetor thoroughly under his control.

It is within the province of the disclosure to improve generally and to enhance the utility of devices of that type to which the present invention appertains.

With the above and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed, may be made within the scope of what is claimed, without departing from the spirit of the inven tion.

In the accompanying drawings:

Fig. 1 shows, in side elevation, a carburetor constructed in accordance with the invention;

Fig. 2 is a top plan;

Fig. 3 is a longitudinal section on the line 33 of Fig. 2;

Fig. 4 is a longitudinal section on the line ll of Fig. 2;

Fig. 5 is a longitudinal section on the line 55 of Fig. 2;

Fig. 6 is an elevation wherein the opposite side of the carburetor is shown "from that depicted in Fig. 9 is a fragmental longitudinal section,

1937, Serial No. 158,403

showing the parts in the position which they will assume at choking or starting status;

Fig. 10 is a view similar to Fig. 9, but showing the parts in idling position;

Fig. 11 is a view similar to Fig. 9, but showing 5 the parts as they will appear when the throttle valve is in Wide open position.

The carburetor forming the subject matter of this application comprises a tubular body I (Fig. 5), including a bowl 2, connected by a tapered portion 3 with a reduced tubular neck 4 having an attaching flange 5, there being a restriction 6 where the tapered portion 3 joins the neck 4.

A shaft 7 is journaled in the neck 4 and carries a throttle valve 8. An arm 9 (Fig. 1) on one end of the shaft 1 constitutes means whereby the shaft may be rocked. The hub of the arm 9 carries a second arm E0, in which is adjustably mounted a stop ll, adapted to engage the flange 5 of the carburetor body.

A third arm 52 (Figs. 1 and 5) is secured to the shaft l, the lower end of a link 14 being pivoted to the arm. The upper end of the link I4 is pivoted to a stud (Fig. 5) movable in a vertically elongated slot it in the bowl 2, the stud being mounted in a rigid hanger l! which is Secured to the flared bell iii of a Venturi member If) which slides in the bowl 2, the extension 20 of the Venturi member sliding in the neck 4, and the slope of the hell it conforming to the slope of the tapered portion 3 of the body I.

Within the bowl 2 is disposed a tubular nozzle carrier 2| (Figs. 4 and 2) supported by a cross bracket 22. One arm of the cross bracket 22 is connected to the bowl 2 by a securing element 23 (Fig. 4), the opposite arm of the cross bracket being secured to the bowl by the threaded and reduced end 2 of a tubular housing 25 located in a horizontal tubular sleeve 26, the housing having a head 2? which engages the outer end of the sleeve. The sleeve 26 (Fig. 2) is formed integrally with a vertical fuel reserve well 28 (Fig. 3), and both the sleeve and the well are formed integrally with the bowl 2. The housing 25 has an external circumferential groove ii], communicating through port's H with the housing, and a passage E9 leads from the well 28 to the groove 10.

A nozzle 29 (Fig. 3) is threaded for vertical adjustment in the carrier 2! and has a tapered lower end 39, the nozzle having an axial bore 3| which is terminated short of the upper end of the nozzle. Within the nozzle carrier 2|, the nozzle 29 is supplied with an external circumscribing groove 32 (Figs. 5 and '7), transverse ports 33 (Fig. 3) in the nozzle establishing communica 55 tion between the groove 33 and the axial bore iii of the nozzle.

The lower portion of the nozzle 29 is surrounded by a downwardly tapered cone valve 34 (Fig. 5), provided at its upper end with a bridge 35 (Fig. 8) having limited vertical reciprocation on the nozzle 29. The vertical reciprocation of the tubular guide portion 39, and consequently the reciprocation of the cone valve 34, is limited by pin projections 37 (Fig. 3) on the nozzle 29, received in vertically elongated slots 38 in the guide 36.

A conical tip 39 surrounds the lower end of the cone valve 34 and extends downwardly with respect to the lower end of the cone valve and with respect to the tapered end 39 of the nozzle 29, the tip being spaced transversely from the cone valve. The tip 39 is connected as shown at 40 (Fig. 5) at oppositely disposed points, to the cone valve 34, but throughout the major portion of its circumference the tip is open at its upper end, as Fig. 9, for example, will show.

In one arm of the cross bracket 22 (Fig. 4) there is a passage 4|, communicating with the reduced end 24 of the housing 25. A seat 42 is secured in the housing 25, adjacent to the reduced end 24 of the housing, and the point of a main needle valve 43 cooperates with the seat. the main needle valve being slidably mounted in a partition 44, threaded to a fixed position in the housing. The main needle valve 43 is provided with an abutment 45 receiving the inner end of a compression spring 45, the outer end of the spring bearing against the end wall of a thimble 4?, the thimble constituting means for adjusting the pressure of the spring. The thimble 41 is threaded into the housing 25 and is held by a lock nut 48 in any position to which it may have been adjusted.

The main needle valve 43 is slidable in the outer end of the thimble 4i, and to the exposed part of the needle valve, an angular operating rod 49 (Fig. 2) is secured by a lock nut 59. The inner end of the operating rod 49 engages the straight edge of an adjusting disk 5! (Fig. 1), in offset relation to a pivot element 52 connecting the adjusting disk to an inverted L-shaped bracket 53, the horizontal portion of which operates in a slot 54 in the upper edge of the bowl 2. The vertical depending part of the bracket 53 is secured (Figs. 4 and 8) to the bell E8 of the Venturi member 19. The adjusting disk 59 is supplied with an arcuate slot 55 (Fig. 1) through which passes a clamp screw 59 that binds the disk to the horizontal part of the bracket 53. The adjusting disk 5i can be shifted to and held in different positions, through the instrumentality of the clamp screw 59, thereby to vary the angle between the straight edge of the adjusting disk and the axis of the operating rod 49. Comparing Figs. 1 and 4, it will be clear that the position of the point of the main needle valve 43 with regard to the seat 42 depends upon the angle between the straight edge of the adjusting disk 5! and the axis of the operating rod 49: and the position of the point of the needle valve 43 with respect to the seat 42 governs the flow of fuel through the seat.

In the inner wall of the reserve well 28 (Figs. 7 and 3) there is a vertical passage 51, leading downwardly to a horizontal bore 58, communicating with the passage 4t in the bracket 22 by way of a port 59 in the reduced end 24 of the housing 25.

A tubular valve housing 69 is threaded into the fuel well 28 and extends across the well, as Fig. 3 will show. The housing 60 communicates with the passage 5'! through a seat 6| in the inner end of the housing. The passage of fuel through the seat BI is controlled by an idling needle valve 92, threaded for longitudinal adjustment at its outer end into the housing 69, and held in place by a lock nut 63. The housing 33 is supplied with an external circumferential groove 64, communicating with the housing through ports in the housing. The groove 64 communicates with a vertical depending inlet member 93, of tubular form, extended downward- 1y into the reserve well 28. The upper portion of the inlet member 66 surrounds the housing 39 and is held in place by lock nuts 61 threaded on the housing. The fuel supply source for the well 28 is marked by the numeral 68, and opens into the well at a place below the housing 50 for the idling valve 62.

The idling conduit includes the source of fuel supply 93 (Fig. 3), the well 28, the inlet member 99, the groove 64, the ports 65, the housing 69, the vertical passage 57, the cross bore 58 of Fig. '1, the port 59, the reduced end 24 of the housing 25, the passage 4! in the bracket 22, the external groove 32 of the nozzle 29 (Fig. 3) and the bore 3! of the nozzle 29.

The running conduit comprises a source 68 of fuel supply, the well 28, the passage 69 (Fig. 7) in the well 28, the circumferential groove 10 of the housing 25, the ports H in the housing 25, the seat 42, the part 24 of the housing 25, the passage 4! in the bracket 22, the circumferential groove 32 (Fig. 3) in the nozzle 29, and the bore 3! of the nozzle 29.

As to gross operation, the shaft 1 of Fig. 3 is rocked through the instrumentality of the arm 9 of Fig. l, the arm I2 actuating the link 64 of Fig. 6, the stud l5 and the hanger H of Fig. 5 imparting vertical reciprocation to the Venturi member l9.

The stop H of Fig. 1 may be adjusted in the arm ll! of the shaft I, so as to bear upon the flange 5 and limit the position of the throttle valve 8 and the Venturi member I9 is in the raised choking or starting position of Fig. 9.

When the Venturi I9 is raised, the rectangular bracket 53 is raised, and when the venturi is lowered, the bracket is lowered also. justing disk 5| of Fig. 1 moves vertically with the bracket 53, and the inclined straight edge of the disk 5! cooperates with the operating rod 49, to impart longitudinal movement to the main needle valve 43 of Fig. 4, thereby adjusting the point of the needle valve with respect to the seat 42, the flow of fuel being regulated accordingly, as the fuel passes into the channel 4!, responsive to engine suction.

With the parts in the choking or starting position of Fig. 9, the cone valve 34 is in engagement with the flared bell N3 of the Venturi I9, and the tapered end 39 of the nozzle 29 is in contact with the reduced lower end of the cone valve 34. At this stage of the operation, there is a suction through the bore 3| of the nozzle 29 only, and the mixture is enriched accordingly, the fuel emerging from the bore 3| of the nozzle 29, as indicated by the arrows 12 of Fig. 9.

In the idling position of Fig. 10, the cone valve 34 remains in contact with the flared bell 18 of the Venturi !9, but the Venturi and the valve have been lowered slightly from the position of Fig. 9, so that the cone valve 34 is free of the tapered end 39 of the nozzle 29, it being possible The adfor the air to flow downwardly between the tapered end of the nozzle and the cone valve, as shown by the arrows 13 of Fig. 10. The tip 39 enhances the flow of air at the lower end of the cone valve 34.

In Fig. 11, which shows the position for a widely opened throttle, the venturi member H! has been lowered until it is out of contact with the cone valve 34, the cone valve being suspended on the nozzle 29, because the pin projections 31 of the fixed but longitudinally adjustable nozzle 29 have arrived at the upper ends of the slots 38 in the guide 36 that is carried by the bridge 35 (Fig. 8) of the cone valve. In addition to the downward flow of air between the nozzle 29 and the cone valve 34, indicated by the arrows 13 in Figs. 10 and 11, there is a downward flow of air between the cone valve 34 and the bell l8 of the venturi H), as indicated by the arrows 14 of Fig. 11.

By a reversal in the direction of movement of the shaft 1, the parts may be restored either to the idling position of Fig. Ill or to the choking or starting position of Fig. 9.

The general construction of the devices is such that it will carry out the objects set forth in the opening portion of this specification.

What is claimed is:

l. A carburetor comprising a body, a nozzle in the body, means for supplying fuel to the nozzle, a valve having limited sliding movement on the nozzle, a venturi slidable in the body, the venturi engaging the valve and the valve engaging the nozzle, to cut off the flow of air to the body, the venturi and the valve being movable together to open an air passage between the valve and the nozzle, the venturi being movable independently of the valve, after the valve has arrived at the limit of its movement, thereby to open another air passage between the venturi and the valve, a throttle valve in the air passage and an operative connection between the throttle valve and the venturi, securing operation of the venturi and the throttle valve in consonance.

2. A carburetor constructed as set forth in claim 1, and wherein the venturi and the valve embody conical parts cooperating to form currents of air which converge at the outlet end of the nozzle, to create a region of reduced pressure and an increase of suction in the nozzle when both of the aforesaid air passages are open, and a conical tip located about the outlet end of the valve and attached to the valve, the tip being open at its top.

WILLIAM SCHWIER. 

